PECASE: Integrated Modeling and Experimental Evaluations of Competition Between PCE-Dehalogenating Populations: Implications for In Situ Bioremediation

提案标题：PECASE：PCE脱卤化种群之间竞争的集成建模和实验评估：对原位生物修复的影响机构：马里兰大学学院园区四氯乙烯(PCE)和三氯乙烯(TCE)是地下水最常见的污染物之一。这些化合物的毒性和物理性质，以及它们被检测到的频率，意味着清理被PCE和TCE污染的地下水系统对保护人类健康至关重要，也是技术上的挑战。PCE的生物转化仅限于厌氧还原脱卤化。从补救的角度来看，只有将PCE完全脱氯为乙烯才是可接受的结果，因为轻微的氯化乙烯也会对健康造成危害。不幸的是，高氯乙烯的完全解毒潜力往往没有就地实现，导致轻氯乙烯的积累。需要更好地了解影响受影响环境中PCE转化程度的因素，以更好地预测污染物的去向和迁移，保护人类健康，并提高生物修复策略的有效性。拟议的研究涉及一种特定类型的微生物相互作用，即脱卤化群体对氯化乙烯的竞争和电子供体之间的竞争。脱卤化种群之间的竞争可能会对就地氯代乙烯的命运产生重大影响，因为这些生物在转化率方面存在差异，更重要的是，脱氯程度不同。拟议的研究目标是：(1)确定脱卤化种群之间的竞争如何受到脱卤化种群的内在生物动力学、可用电子供体的性质和浓度以及氯化乙烯浓度的影响；(2)开发工具来预测脱卤化种群之间竞争的结果，对氯化乙烯命运的影响，以及生物强化策略的成功。这些目标将通过一种综合方法来实现，包括在一系列日益复杂的实验系统中进行建模、预测和验证，包括确定的共同培养竞争实验和涉及受多氯乙烯影响地点地下水的微生物和化学特征的实地调查。将通过基于16S rRNA的方法实现地下水系统中关键的PCE脱卤化种群的量化。该项目最初是作为职业奖资助的，并于2004年5月转变为总统工程师和科学家早期职业奖(PECASE)。

Proposal Title: PECASE: Integrated Modeling and Experimental Evaluations of Competition Between PCE-Dehalogenating Populations: Implications for In Situ BioremediationInstitution: University of Maryland College ParkThe chlorinated solvents tetrachloroethene (PCE) and trichloroethene (TCE) are among the most common contaminants of groundwater. The toxicity and physical properties of these compounds, along with the frequency with which they are detected, mean that cleanup of groundwater systems contaminated with PCE and TCE is both critical to protecting human health and technically challenging. Biological transformation of PCE is limited to anaerobic reductive dehalogenation. From a remediation standpoint, only complete dechlorination of PCE to ethene is an acceptable outcome, because lightly chlorinated ethenes also pose a health hazard. Unfortunately, the potential for complete detoxification of highly chlorinated ethenes is frequently not realized in situ, resulting in the accumulation of lightly chlorinated ethenes. An improved understanding of the factors that influence the extent of PCE transformation that occurs in impacted environments is needed to better predict contaminant fate and transport, protect human health, and improve the effectiveness of bioremediation strategies. The proposed research addresses a specific type of microbial interaction, competition between dehalogenating populations for chlorinated ethenes and electron donors. Competition between dehalogenating populations may have a major impact on the fate of chlorinated ethenes in situ because these organisms differ with respect to transformation rates, and even more importantly, the extent of dechlorination.The goals of the proposed research are:(1) to determine how competition among dehalogenating populations is influenced by the intrinsic biokinetics of the dehalogenating populations, the nature and concentrations of the available electron donors, and chlorinated ethene concentrations; and (2) to develop tools for predicting the outcome of competition between dehalogenating populations, the impact on chlorinated ethene fate, and the success of bioaugmentation strategies. These goals will be accomplished using an integrated approach involving modeling predictions and verification in a series of increasingly complex experimental systems, including defined co-culture competition experiments and field surveys involving microbiological and chemical characterization of groundwater at PCE-impacted sites. Quantification of key PCE-dehalogenating populations in groundwater systems will be achieved through 16S rRNA-based methods. This project was originally funded as a CAREER award, and was converted to a Presidential Early Career Award for Engineers and Scientists (PECASE) award in May 2004.